Tuesday, October 31, 2006

Brilliant but borderline psychotic surgeon does secretive, experimental work with limb transplants and tissue rejection drugs, much to the chagrin of his surgeon-father. When he crashes his car and his fiancee is decapitated, his research - far from complete - is put to the test. His focus then becomes finding an appropriate donor body to make his fiancee whole, while the current and failed experiments in his basement laboratory grow restless.

Monday, October 30, 2006

Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. We exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus "mark test" for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.

To date, one investigation failed to find mirror self-referential behavior in Asian elephants while another reported positive results, a contradiction which could, among other things, be ascribed to the poor visual acuity of elephants. To resolve this contradiction, the present study of mirror self-referential behavior in two captive Asian elephants bypasses the traditional mark test, relying instead on the elephants’ response to a far more visually conspicuous object. In this study, neither elephant engaged in self-referential behavior in front of a mirror. Our simple experimental paradigm could serve as a more convenient alternative to the widely used traditional mark test, could meet some methodological objections which have been raised against the traditional mark test, and could profitably augment the traditional test in difficult or controversial cases.

...social environment affects the amount of sleep. Fruitflies kept in isolation sleep less than fruitflies kept in groups. As these insects already sleep through the night, the only time where additional sleep can be fitted in is during daytime - taking naps. Flies in group settings did not have more naps, but their naps lasted much longer. The volume of the environment (the size of the vial) had no effect on this. On the other hand, the number of flies kept together did matter: more flies in the vial, longer the naps.

. . .

Put together, the paper provides evidence at several different levels of organization (genetics, neurochemistry, development, behavior) that sleep in fruitflies is related to learning and memory of social interactions.

Researchers at the Woods Hole Marine Biological Laboratory have for the first time identified a short peptide which 'tags' cellular cargo for transport along a neuron's axon. The peptide is a short fragment of amyloid precursor protein, which many believe is responsible for the neuropathology of Alzheimer’s disease.

I take you on a very unusual journey into the step-by-step deterioration of my cognitive abilities, as viewed through the eyes of a scientist. As the hemorrhage in my brain grew larger and larger, I relate the cognitive deficits I was experiencing to the underlying biology. As a neuroanatomist, I must say that I learned as much about my brain and how it functions during that stroke, as I had in all my years of academia.

Tuesday, October 24, 2006

You can't see them here, because the authors exploited the phenomenon of binocular rivalry to present different images to each eye separately. Specifically, dynamic visual noise and nude male or female images were presented to each eye simultaneously. The visual noise in one eye suppresses the naked body in the other, making its perception unconscious.

In an experiment, 40 men and women were shown erotic images that had been manipulated to bypass conscious detection. The participants consisted of both heterosexual and homosexual individuals.

Subjects were then shown a small "probe" pattern and asked to determine its orientation -- clockwise or counterclockwise. The researchers found that subjects identified the probe pattern more accurately when it appeared where the erotic images had been, suggesting that the invisible images exerted an effect on their spatial attentions.

In general, the erotic images attracted or repelled attention depending on the gender of the nude model and also the sexual orientation of the subject. For example, heterosexual males tended to perform better on the pattern task when it followed the presentation of an invisible female nude than a male nude. Gay males, in contrast, showed more enhanced performance when exposed to invisible male nudes compared to female nudes.

. . .

For women, the results were more mixed. Heterosexual females performed better after exposure to invisible male nudes, but their performance didn't necessarily worsen when exposed to female nudes. [NOTE: that doesn't sound like "repels."]

The performances of homosexual and bisexual females were somewhere in-between heterosexual male and heterosexual female groups.

The paper was supposedly published online yesterday in Proceedings of the National Academy of Sciences, but it's nowhere to be found. We'll just have to make do with LiveScience.com for now.

Saturday, October 21, 2006

The nub of Dawkins’s consciousness-raising message is that to be an atheist is a "brave and splendid" aspiration. Belief in God is not only a delusion, he argues, but a "pernicious" one. On a scale of 1 to 7, where 1 is certitude that God exists and 7 is certitude that God does not exist, Dawkins rates himself a 6: "I cannot know for certain but I think God is very improbable, and I live my life on the assumption that he is not there."

Wednesday, October 11, 2006

An estimated 655,000 more Iraqis have died as a consequence of the March 2003 military invasion of Iraq than would have been expected in a non-conflict situation, according to an article in The Lancet:

Background An excess mortality of nearly 100 000 deaths was reported in Iraq for the period March, 2003-September, 2004, attributed to the invasion of Iraq. Our aim was to update this estimate.

Methods Between May and July, 2006, we did a national cross-sectional cluster sample survey of mortality in Iraq. 50 clusters were randomly selected from 16 Governorates, with every cluster consisting of 40 households. Information on deaths from these households was gathered.

Findings Three misattributed clusters were excluded from the final analysis; data from 1849 households that contained 12,801 individuals in 47 clusters was gathered. 1474 births and 629 deaths were reported during the observation period. Pre-invasion mortality rates were 5·5 per 1000 people per year (95% CI 4·3-7·1), compared with 13·3 per 1000 people per year (10·9-16·1) in the 40 months post-invasion. We estimate that as of July, 2006, there have been 654,965 (392,979-942,636) excess Iraqi deaths as a consequence of the war, which corresponds to 2·5% of the population in the study area. Of post-invasion deaths, 601,027 (426,369-793,663) were due to violence, the most common cause being gunfire.

Interpretation The number of people dying in Iraq has continued to escalate. The proportion of deaths ascribed to coalition forces has diminished in 2006, although the actual numbers have increased every year. Gunfire remains the most common cause of death, although deaths from car bombing have increased.

That's the title of a book (2003, Farrar, Straus & Giroux) by the late Susan Sontag.

''Let the atrocious images haunt us. Even if they are only tokens, and cannot possibly encompass most of the reality to which they refer, they still perform a vital function. The images say: This is what human beings are capable of doing -- may volunteer to do, enthusiastically, self-righteously. Don't forget.''

Images are one thing. We shouldn't forget them. But what happens to a person when he loses his empathy?

ROME, March 7 (Reuters) - A U.S. soldier who raped a Nigerian woman in Italy was given a lighter sentence because the court deemed his tour of duty in Iraq had made him less sensitive to the suffering of others.

And what sort of empathy did the Italian judges feel for the Nigerian victim??

Empathy is a complex social behaviour mediated by a network of brain structures. Recently, several functional imaging studies have investigated the neural basis of empathy, but few corroborative human lesion studies exist. Severe empathy loss is a common feature of frontotemporal lobar degeneration (FTLD), and is also seen in other neurodegenerative diseases. In this study, the neuroanatomic basis of empathy was investigated in 123 patients with FTLD, Alzheimer's disease, corticobasal degeneration and progressive supranuclear palsy using the Interpersonal Reactivity Index (IRI). IRI Empathic Concern and Perspective taking scores were correlated with structural MRI brain volume using voxel-based morphometry. Voxels in the right temporal pole, the right fusiform gyrus, the right caudate and right subcallosal gyrus correlated significantly with total empathy score. Empathy score correlated positively with the volume of right temporal structures in semantic dementia, and with subcallosal gyrus volume in frontotemporal dementia. These findings are consistent with previous research suggesting that a primarily right frontotemporal network of brain regions is involved in emotion processing, and highlights the roles of the right temporal pole and inferior frontal/striatal regions in regulating complex social interactions. This is the first large-scale lesion study to investigate the neural basis of empathy using correlational analytic methods. The results suggest that the right anterior temporal and medial frontal regions are essential for real-life empathic behaviour.

de Vignemont F, Singer T. (2006). The empathic brain: how, when and why?Trends Cog Sci. 10:435-41.Recent imaging results suggest that individuals automatically share the emotions of others when exposed to their emotions. We question the assumption of the automaticity and propose a contextual approach, suggesting several modulatory factors that might influence empathic brain responses. Contextual appraisal could occur early in emotional cue evaluation, which then might or might not lead to an empathic brain response, or not until after an empathic brain response is automatically elicited. We propose two major roles for empathy; its epistemological role is to provide information about the future actions of other people, and important environmental properties. Its social role is to serve as the origin of the motivation for cooperative and prosocial behavior, as well as help for effective social communication.

Monday, October 09, 2006

Annie [the unbalanced "number one fan" of Paul Sheldon's romance novels] rescues the injured Sheldon from a car accident and seizes the opportunity to nurse her favorite writer back to health, but her tender loving care soon turns to terrorism as she demands that Sheldon write his latest novel according to her wish-fulfillment fantasies.

Annie the nurse initally offers empathy and narcotics, but her nuturing devolves into brutality... which leads us to today's topic: Is pain the price of empathy? A recent paper in Brain examined whether people born without the capacity to feel physical pain are capable of recognizing pain in others:

Empathy is a complex form of psychological inference that enables us to understand the personal experience of another person through cognitive/evaluative and affective processes. Recent findings suggest that empathy for pain may involve a 'mirror-matching' simulation of the affective and sensory features of others' pain. Despite such evidence for a shared representation of self and other pain at the neural level, the possible influence of the observer's own sensitivity to pain upon his perception of others' pain has not been investigated yet. The aim of this study was to explore how patients with congenital insensitivity to pain (CIP), who are largely deprived of common stimulus-induced pain experiences, perceive the pain of others. Ratings of verbally presented imaginary painful situations showed that CIP patients' semantic knowledge regarding the pain of others did not differ from control subjects. Moreover, the propensity to infer pain from facial expressions was very similar between CIP patients and control subjects. On the other hand, when asked to rate pain-inducing events seen in video clips in the absence of visible or audible pain-related behaviour, CIP patients showed more variable and significantly lower pain ratings, as well as a reduction in aversive emotional responses, compared with control subjects. Interestingly, pain judgements, inferred either from facial pain expressions or from pain-inducing events, were strongly related to inter-individual differences in emotional empathy among CIP patients, while such correlation between pain judgement and empathy was not found in control subjects. The results suggest that a normal personal experience of pain is not necessarily required for perceiving and feeling empathy for others' pain. In the absence of functional somatic resonance mechanisms shaped by previous pain experiences, others' pain might be greatly underestimated, however, especially when emotional cues are lacking, unless the observer is endowed with sufficient empathic abilities to fully acknowledge the suffering experience of others in spite of his own insensitivity.

These CIP patients have a rare hereditary sensory and autonomic neuropathy (HSAN) of small nerve fibers that usually transmit painful inputs along sensory nerves. It's really not a good thing (see for yourself, BUT BE WARNED, gory photos)... some cases are associated with self-mutilation in childhood. So these individuals have a problem with the peripheral nervous system, not the all-powerful, centrally-located mirron neuron system. Based on ideas like embodiment, if someone can't feel pain, they can't run a bodily simulation of a painful experience (or at least, its affective component); ergo, they can't identify and empathize with another's pain.

Twelve patients with CIP participated in the study. They showed a dramatic sensory loss for pain since birth, affecting the whole body.

All patients showed a complete lack of discomfort, grimacing or withdrawal reaction to prolonged pinpricks, strong pressure, soft tissue pinching and noxious thermal stimuli (0 and 50 degrees C) applied to the proximal and distal parts of the four limbs and to the face.

The patients (and a large group of control participants) filled out both "self" and "other" versions of the Situational Pain Questionnaire, rating items like "I get a tooth drilled without a pain killer" and "I get a mosquito bite" on a scale of 1 to 10. They also watched video clips from the Accident and Injury categories of Stupidvideos.com, such as...

Skate-board fall on the backBoxer suffering a severe ankle strainWoman falling forward on a treadmillGymnast falling from horizontal barMissed jump from a diving-board

...and then rated the amount of pain experienced by the injured individuals on a scale of 1 to 10. The video clips didn't show the injured parties' facial expressions, but the Sensitivity to Expressions of Pain test did. Finally, a measure of general empathy (the "tendency to feel and vicariously experience the affective experiences of others") was obtained using the Balanced Emotional Empathy Scale and related to the measures of feeling another's pain.

So were the CIP patients impaired in Regarding the Pain of Others? On the Situational Pain Questionnaire, those with CIP did not differ from controls in rating the pain of others. The Sensitivity to Expressions of Pain ratings and emotional empathy scores did not differ between the two groups, either. In contrast, ratings of the Jackass-type video clips (which didn't present visible or audible expressions of pain) were generally lower.

The authors conclude thusly:

In his novel Ingenious Pain, contemporary novelist Andrew Miller created a central character who is born unable to feel pain and who grows into a technically skilled but unfeeling surgeon (Miller, 1997). Contrary to the theory supported by the plot of this novel (Loeser, 2005), our results suggest that a normal personal experience of pain is not necessarily required for perceiving and feeling empathy for others’ pain. In the absence of functional somatic resonance mechanisms shaped by previous pain experiences, others’ pain might be greatly underestimated, however, especially when emotional cues are lacking, unless the observer is endowed with sufficient empathic abilities to fully acknowledge the suffering experience of others in spite of his own insensitivity.

Thursday, October 05, 2006

Whether you're a future graduate psychologist, a hardened lab-based neuroscientist or are in the midst of studying any of the cognitive sciences, we should have something to help you on your way.

Not that The Neurocritic is personally promoting anyone who appeared on that list, mind you. But I will promote Vaughan's collaboration with artist Simon Pope:

Gallery Space Recall was developed as part of Walking Here And There, a research project undertaken in collaboration with the psychologist Vaughan Bell. A book documenting this exhibition and other research outcomes will be produced later in the year.

Changing Minds: Area 25Experimental Brain Surgery May Help The Severely Depressed(CBS) Eighteen million Americans suffer from major depression. Most of them are treated successfully with a combination of “talk therapy” and anti-depressant drugs. But millions of Americans – possibly as many as four million - are afflicted with what is known as “treatment-resistant” depression. For them, nothing works, not even electric shock treatments. They endure lives of debilitating sadness and some end up committing suicide.But as correspondent Lesley Stahl reports, early results from an experiment in Canada have raised hopes for an answer to their suffering. It involves surgery on a region of our brains called Area 25. And, for the small group of patients who have signed up, the risks seem worth taking, because this is their last resort.

existential (or melting-reality) sort of way. But in a new study, ibotenic acid-induced lesions in the rat rostral cingulate cortex were associated with subsequent impairment in the forced swim test:

The forced swim test (FST) is the most widely used model for assessing potential antidepressant activity in rodents following acute or short-term treatment.

We can certainly protest (quite loudly) that "giving up and floating around the pool" behavior is not much of a model for human depression, but rats aren't very well going to be up all night listening to Bright Eyes or Radiohead and reading Beckett. Moreover, is rat rostral ACC comparable to human ventral ACC? It's interesting that Mayberg et al. (2000) found that resting glucose metabolism in ventral ACC to be overly active in depressed people (and a reduction in activity was associated with antidepressant treatment response), but here we see that permanent damage to rostral ACC in rats acted as a pro-depressant:

Bissiere S, McAllister KH, Olpe HR, Cryan JF. (2006). The rostral anterior cingulate cortex modulates depression but not anxiety-related behaviour in the rat. Behav Brain Res. Sep 30; [Epub ahead of print]A growing body of functional imaging studies suggests that human depression and anxiety symptoms are associated with functional abnormalities in the circuitry formed by the rostral anterior cingulate cortex (rACC) and its direct limbic and paralimbic connections. In rodents however, the role of the rACC (rCG1/rCG2) remains unknown in depression-related behaviours and elusive in acute anxiety. In order to address this, we specifically lesioned the rat rCG1/rCG2, and assessed the behavioural outcome using a modified forced swim test (FST) and the elevated plus maze (EPM), tests for depression and anxiety related behaviours respectively. Lesions of the rostral anterior cingulate cortex significantly increased the time spent immobile in the FST without affecting climbing or swimming performances, suggesting a pro-depressant effect. On the contrary, none of the parameters measured in the EPM was affected by the lesion. These data point to an involvement of the rCG1/rCG2 in depression-related coping behaviours.

However, other investigators find that resting metabolic activity in ventral ACC is reduced in both unipolar and bipolar depression (Drevets et al., 1997), more in agreement with the rat study, but contrary to Mayberg et al. What's up with that? Here's what Mayberg et al. (2005) suggest:

The baseline pattern of subgenual cingulate hyperactivity in combination with frontal hypoactivity described here in this TRD patient group is a finding that is in contrast to the hypoactivity reported in a more rostral region of subgenual medial prefrontal cortex in familial bipolar and unipolar depressed patients (Drevets et al., 1997). This distinction suggests important differences across subtypes of depression that are potentially relevant to the pathophysiology of major depressive disorders and perhaps their treatment.

And here, you can screen your own mental health using a self-assessment program.

The house is reelingI'm kneeling by the tubLonely is as lonely doesLonely is an eyesoreThe feeling describes itself--Throwing Muses, Fish

About Me

Born in West Virginia in 1980, The Neurocritic embarked upon a roadtrip across America at the age of thirteen with his mother. She abandoned him when they reached San Francisco and The Neurocritic descended into a spiral of drug abuse and prostitution. At fifteen, The Neurocritic's psychiatrist encouraged him to start writing as a form of therapy.